The blowing operation is effected by a blow head. Conventionally the blow head is brought into position on top of (engaging) a blow mold at the blow station and provides air (“final blow”) under pressure through a downwardly extending blow tube to the interior of the parison to blow the parison into contact with the interior of the blow mold. The parison could also be formed with vacuum or with a vacuum assist. The blown parison must then be formed into a bottle, i.e., cooled to the point where it is rigid enough to be gripped and removed from the blow station by a takeout mechanism. The outer surface of the blown parison is cooled by cooling the blow molds and the inner surface of the blown parison is cooled by the final blow air which continues to flow into the blown parison. U.S. Pat. No. 4,726,833 discloses a state of the art blow head. Conventionally the cooling air escapes from the interior of the bottle through a permanently open exhaust. The size of the exhaust will be defined as a balance between inlet and outlet.
Before a conventional takeout can be displaced from a remote location to a pick up location proximate the top of the formed bottle, the blow head, including the blow tube, must be displaced away from the blow mold. This displacement must be at least to a position where it will not interfere with an inwardly moving takeout. To speed up these steps, U.S. Pat. No. 5,807,419, proposes a combined blow head and takeout mechanism. This mechanism permits the operation of takeout jaws as soon as the blow head, which engages the top of the blow molds during final blow, is slightly elevated, with the blow tube remaining fully extended and operating, following the formation of the bottle. The takeout jaws immediately reseal the blow head. The internal cooling of the bottle will accordingly continue as if the blow head was in place on top of the blow mold while the bottle is removed from the blow mold and carried to a dead plate on which it will be deposited. The cooling of the outer surface of the formed bottle stops with the opening of the blow molds.
U.S. Pat. No. 4,508,557, discloses a dead plate arrangement for blowing cooling air around the bottle to provide additional outer surface cooling on the deadplate. U.S. Pat. No. 4,892,183 discloses a dual take-out mechanism which functions to alternately remove bottles from the blow station placing half on one output conveyor and the other half on a second output conveyor.
In all of these systems, the bottles once removed from the deadplate, will be conveyed into a Lehr which utilizes a series of burners to immediately reheat the bottles to a uniform higher temperature and then allows the bottles to cool slowly before being discharged from the Lehr.
Formed bottles have also been tempered in separate machinery by reheating the bottles and then simultaneously cooling the inner and outer glass surfaces (see for example, U.S. Pat. No. 2,309,290).